• Journal of Surface Science and Engineering
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• v.57 no.4
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• pp.234-253
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• 2024

As the population ages, the importance of effective bone disease treatments is increasing, highlighting the role of bone grafts. Bone grafts are categorized into natural (autografts, allografts, xenografts) and synthetic (ceramics, polymers). Natural grafts have excellent regenerative abilities but pose biological risks, while synthetic grafts are biocompatible but less effective in regeneration. Various studies aim to enhance the safety and efficacy of bone grafts, significantly altering their surface properties. This review examines these studies and the resulting surface changes, aiming to guide future research and clinical applications.

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.82.2-84
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• 2000

No Abstract, See Full Text

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.3
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• pp.121-122
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• 2019

• Journal of Plant Biotechnology
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• v.45 no.2
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• pp.146-153
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• 2018

Lilium ledebourii Bioss is a wild species of Lilium, which grows naturally in some provinces of Iran. Previous studies on Lilium tissue culture have been linked to direct regeneration and a few studies have been conducted on indirect regeneration, which has been studied under bright conditions. In this study, for the first time in the world, all the stages of indirect regeneration (callus induction, shoot and root induction) have been studied under dark conditions. Callus formation and the regeneration levels of L. Ledebourii Bioss were examined for three replicates in an MS (Murashige and Skoog) medium with different hormonal compositions and by using a factorial experiment in the framework of a completely random plan. For callus initiation, 2,4-D and kinetin hormones were used in five and four levels, respectively, as auxin and cytokinin. Results showed that the highest percentage of the callus was found in $3{\mu}M$ of 2,4-D and $0.5{\mu}M$ of kinetin. In terms of callus wet weight, the highest amount was found in $3{\mu}M$ of 2,4-D and $0.5{\mu}M$ of kinetin. In addition, in terms of diameter, the highest amount was found in $3{\mu}M$ of 2,4-D, and $0.5{\mu}M$ of kinetin. In summary, the 2,4-D hormone had a major impact on the percentage of regeneration increase so that the best response was related to the composition of $3{\mu}M$ of 2,4-D, and $0.1{\mu}M$ of kinetin. This study contended that auxin and cytokinin can induce long shoots and roots through cell elongation in dark condition.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.04a
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• pp.185-185
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• 2003

• Journal of Korean Neurosurgical Society
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• v.53 no.2
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• pp.65-71
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• 2013

Objective : In order to develop a novel nerve guidance channel using porcine small intestinal submucosa (SIS) for nerve regeneration, we investigated the possibility of SIS, a tissue consisting of acellular collagen material without cellular immunogenicity, and containing many kinds of growth factors, as a natural material with a new bioactive functionality. Methods : Left sciatic nerves were cut 5 mm in length, in 14 Sprague-Dawley rats. Grafts between the cut nerve ends were performed with a silicone tube (Silicon group, n=7) and rolled porcine SIS (SIS group, n=7). All rats underwent a motor function test and an electromyography (EMG) study on 4 and 10 weeks after grafting. After last EMG studies, the grafts, including proximal and distal nerve segments, were retrieved for histological analysis. Results : Foot ulcers, due to hypesthesia, were fewer in SIS group than in Silicon group. The run time tests for motor function study were 2.67 seconds in Silicon group and 5.92 seconds in SIS group. Rats in SIS group showed a better EMG response for distal motor latency and amplitude than in Silicon group. Histologically, all grafts contained some axons and myelination. However, the number of axons and the degree of myelination were significantly higher in SIS group than Silicon group. Conclusion : These results show that the porcine SIS was an excellent option as a natural biomaterial for peripheral nerve regeneration since this material contains many kinds of nerve growth factors. Furthermore, it could be used as a biocompatible barrier covering neural tissue.

• Journal of Drive and Control
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• v.9 no.1
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• pp.10-17
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• 2012

Nowadays, the demand of energy saving is increasing more and more while the natural resources have been exhausted. Besides, the emission gas caused by vehicles has been being a serious environment problem. Therefore, many studies have been carried out, especially focusing on braking energy regeneration, in order to save energy as well as reduce emission of mobile vehicles. In this paper, we propose a closed-loop hydrostatic transmission for braking energy regeneration with two configurations to reduce the energy consumption by recovering the braking energy. The effectiveness of the proposed system was verified by simulation. The simulation results indicated that the pressure coupling configuration gave better performance in comparison to flow coupling configuration about 40.8%, 61.7% and 53.8% reduction of fuel consumption in 10 mode, 10 mode modified profile and highway schedules, respectively.

• Journal of the Korean Wood Science and Technology
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• v.26 no.3
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• pp.81-92
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• 1998

Lately public interest in tree saps of maple and birch trees has been increased for sap drink as a natural medical beverage. To ensure tree sap drink for commercial production, species which are available in resources, their ecological regeneration characteristics in the natural forest stand, and tree sap resources should be investigated. Species for the collecting tree saps and their distribution were surveyed in the areas of Mt.Sobaek, Tanyang-gun, Chungcheongbuk-do. Mt.Sobaek area was selected to the proper place to survey as the feasible area for tapping tree saps for the natural beverage. Feasible tree species of this area are Betula costata, Betula schmidtii, Comus controversa, Acer mono, and Acer pseudosieboldianum based on the estimated tree sap amounts. Average and maximum species diversities of surveyed area were 4.2 and 5.39, respectively. Its evenness 0.78 referred that there are actively progressing ecological regeneration among diverse tree species. Tree saps are mainly harvested at the areas of upper and lower Wonmanteo. In terms of species, the most high sap amounts were from birch sap, next Comus controversa, the 3rd Acer mono. Many measures were suggested ecologically and technically, for commercial or practical production of tree sap drinks, though Mt.Sobaek area was evaluated as improper place because of geographical and transportational limitation.

• Journal of Ecology and Environment
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• v.34 no.4
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• pp.347-355
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• 2011

Effects of forest thinning on community level properties have not been understood yet in Korea. We investigated regeneration patterns and trajectories after a disturbance by applying a chronosequence approach. Light availability, litter and woody debris cover, and species composition were determined for twenty 50 m line-transect samples representing a disturbance duration gradient (within 11 years). Environmental factors such as light availability and coverage of woody debris and litter changed abruptly after thinning and then returned to the pre-disturbance state. Although species richness was gained at shrub and ground layer in a limited way in both forests, cover of various functional types revealed diversity in their responses. Notably, Alnus firma stands exhibited a larger increment of cover in woody plants. Ordination analysis revealed different regeneration trajectories between natural and planted stands. Based on ordination analysis, rehabilitated stands showed movement to alternative states compared with natural ones, reflecting lower resilience to perturbation (i.e., lower stability). Our results suggest that community resilience to artificial thinning depends on properties of the dominant species. But to get more explanatory ecological information, longer-term static observations are required.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.42-47
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• 2016

To examine the natural regeneration in the natural mixed-broadleaved forest, flowering, fruiting, seed-fall, and seed viabilities of Acer pseudosieboldianum (Ap) were investigated in Mt. Jungwang, Gangwon-do, from 2009 to 2015. The flower of Ap consisted many male and bisexual flowers on the corymb. Flowering dates are differed between sex morph in the same inflorescence. Stamens are stop growing and disappeared after pollinated pistil begin to grow in bisexual flowers, and male flowers have vestial pistil. The flowers of Ap might be pollinated by Apis mellifera, Andrenidae spp. and Syrphinae spp. Ap had some mechanism to prevent from self pollination with heterodichogamy. Mean annual seedfall of Ap was 70,780 ea/ha (ranged 310~234,840 ea/ha). Annual seedfall of Ap varied severely, and the maximum was about 760 times the minimum. Annual seed production of Ap might be to a normal distribution. Rates of damaged or decayed seeds are highest 59.3%, and those of sound seeds are 23.9%, Those of undeveloped and empty seeds are 9.2% and 7.6%, respectively. The most important factors influencing sound seed production might be the density and activities of insect pollinators and sucking pest in the flowerwing period, middle-late May. Successful regeneration of Ap might be in masting year and on the gap sites with proper conditions to germinate and grow. To understand the natural regeneration of deciduous hardwoods, further study on the characteristics of flowering and fruiting, pre- and post-dispersal seed predation, and annual variation on these factor should be needed.